1. Field of the Invention
This invention relates to antennas for use in wireless communication systems, and more particularly to an antenna module containing multiple co-located antennas with a plurality of active control elements for dynamically tuning the antenna module over multiple bands.
2. Description of the Related Art
As new generations of handsets and other wireless communication devices become smaller and embedded with increased applications, new antenna designs are required to address inherent limitations of these devices and to enable new capabilities. With classical antenna structures, a certain physical volume is required to produce a resonant antenna structure at a particular frequency and with a particular bandwidth. In multi-band applications, more than one such resonant antenna structure may be required. But effective implementation of such complex antenna arrays may be prohibitive due to size constraints associated with mobile devices.
Current wireless devices contain multiple antennas that are used to service a wide variety of functions including cellular, GPS, Bluetooth, WLAN, FM, WiMax, and others. Typically these antennas are distributed around the wireless device and the performance of the total antenna system is optimized per device. Substantial resources are expended in an effort to prepare the multi-antenna system to operate in an optimized state, with this time consuming process needing to be repeated from one product to the next. The small size of current wireless devices substantially effects antenna performance due to the dependence of the antenna on the size of the ground structure that the antenna is coupled to. The circuit board of the wireless device provides the ground plane function for the antenna. The circuit board dimensions are chosen to accommodate the wireless circuit and cannot be optimized for antenna performance. A ground plane that is one quarter wave length in extent is optimal for antenna performance, which results in antenna performance varying greatly over wide frequency bandwidths.
A solution is hereby proposed which yields an antenna system module configured to contain one or more co-located active and passive antennas, and a number of active control elements within a common assembly. The antenna system module will provide simplified installation and tuning of the antennas as well as a small form factor for containing multiple antennas and is dedicated to supporting a variety of multi-media applications, including one or more of: cellular communications, GPS, FM, Bluetooth, WLAN, and WiMax, among others.